Control of slime organisms



.andoontrol of such conditions;

In pulp and paper mills, slimy growths 'fre-s Patented May 21, 1946.

: mes STATE William'W. AllcnrMidlandr Mich asllgnor to 3 TheDowChcmicalCompany,ltildland ,lifloh- ,a f

corporation of Michigan Serial N- 498,411

No Application August 12, 1943,

i I 40mm. (ciao-2s) The present invention is concerned with the directed to a method forpreventing the formawater systems by adding to the water a combination of toxic materials, ,andto a mixture of toxicants so employed.

. The development of slime organisms in circu- 1 iating water systems, constitutes a maior problem in power plants, sugar refineries, distiller-lea, pulp,

' paper, and paper-,b0ard mills, andothe'r industries. The tendency'for slimy deposits and shine bodies to clog pipes or conduits so as to interfere. with the circulation of water. aqueous solutions,

and-suspensions andto discolor or otherwise concontrol of slime organisms, and i'sparticuiarly tion of slime bodies and deposits in circulating and the polychlorophenols I and their salts.

Knowing the nature oi the slimy deposits and bodies produced within a given circulating system, it has been possible to-employ particular chemicalcompounds to kill or suppress specific organisms. Unfortunately, however, to accomplish a .quick control of the assorted micro-flora within any given system, it has been found neces sary to employ a multiplicity-of treatments each specific to but one or to "a-small group of the organisms concerned. Thus,- in a representative mill, copper sulfate might well be, employed to taminate products contacted therewith vor with slime-encrusted machinery andapparatus has chemists and others interested in the prevention long been the subjects-of investigation by biouuentlybecome' associated with'th'e' celiulosic pulp and cause the discoloration and eventual decomposition of the finished; product. Also.

pipes, screens, calender boxes," and the like, at certain times of the year become so choked with; j gelatinous or semi-solid deposits asto necessitate temporary suspension-of production and intensive cleaning and sterilizing operations. In air-conditiming systems, distilleries, power piants'and the like, wherein cooling water is circulating through container orv coils, the deposits of micro-organisms not only obstruct the flow of liquids through in such fashion as to maintain in the system in-' hibitory and/or toxic concentrations of the-sev- Y eral toxicants employed. Y

phenols and their solublesaits in conflnedcirculating water systems for the control of microcontrol algae or a slime-forming fungi, but chlorlne or chloramine would be required in order to accomplish the inhibition of bacterial In the same system it might further be necessary or desirable to-empioy a zinc salt or other bactericidal material to control organisms not vulnerabie to the action of copper sulfate and chic-f rine. Buchmultiphase' control methods are ex'- pensive, time-consuming, and not always reliable,

either by reason of the presence in the system of.

organisms not controlled'by any one of the se eral toxicants employed or by failure-of the operator to carry out the addition of the toxicants A recent development in slime andalgae control has been that of employing the polychloroorganisms. While the use of these compounds the pipes, lets, valves, etc., but frequently lead to' problems of corrosion where hydrogen sulfidegenerating organisms are present in thewater employed or'rbecome established through the A further difncuity. encountered with certain alimesand related organisms-is that-of odor.

Many of the slime-forming bacteria,'particularly of the anaerobic typ are directly responsible for the development of odors which are highly obmake desirable the provision of improved methods and compositions. Thus, while low dilutions iectionable under-any conditions, but more par-- ticularly. when imparted to and taken up by food products, paper and paper-board to be employed in food containers, and the like. The foregoing problems have led to the development of a wide variety of treatments for-the control of slimeforming bacteria, yeasts, fungi, and algae.

Among the products which have been employed for thecontroi of slime and algae are such varied materials as chlorine, chloramine T, chlorineammonia complexes, copper sulfate, potassium permanganate, mercury derivatives. zinc salts.

, inhibition is initially obtained, inhibiting conconstitutes a'deilnite advance over the control measures previously available, there are certain limitations'with respect to their, use in the control of slime-forming bacteria and fungi which of such phenol compounds may give control against certain of thealgae and filamentous fungi of the mold type such as members of the genera 'Penicillium, Aspergillus, and Trichoderma, they do not accomplish a quick kill of coliiormand coliform-like bacteria such as the genera Escherichia and Aerobacter, spore-bearing types such as Bacillus peptogenes and Bacillus megatherium,

and pseudo yeasts and yeast-like fungi such as Oidium, except at excessively high concentrations.

Also the polychlorophenols and their simple salts are so fugitive that, even though a measure of centrations of the toxicant must be continually added to and maintained in the system else-the mycelia and spores of the temporarily controlled "As-has been indicated,

organisms resume growth, frequently in a more prolific fashion than prior to treatment. It is an object of the present invention to prochlorophenolate, potassium li-trichlorophenolate, ammonium 2.4.5-trichiorophenolate, triethvide an improved method and composition for the control of all slime-forming and related microv organisms. It is a further object 'to supply such a composition which will be effective at lower concentration's than those hitherto known. 'An additional object is to provide a method and compo-x sitlon for slime control which will accomplish a quick kill of the objectionable organisms rather anolamine salt of 2.4.5-trichlorophenol, sodium 2;4.6-trichlorophenolate. ammonium 2.4:.iitrichlorophenolate, sodium2.5.6-trichlorophenolate,

- sodium 2.3.4-trichlorophenolate, potassium 3.4.5- 1 trichlorophenolate, etc. A

than a temporary inhibition or delayed control such as has characterized control measures heretofore employed. Other objects of the invention,

will become apparent from the following sp cification and examples.

I I have discovered that the disadvantages "ac cruing to known slime control methods can be irophenolates.

largely avoided by the use of a combination of e (A) a water-soluble coppersalt'and (B) a watersoluble'trichlorophenolate as the effectivetoxic principal. solutions and suspensions of low, concentrations 01" copper ionsand of trlchlorophenol molecules accomplishes a quick killof slime-forming and related organisms generally, :50 that supplemen tary-control measures'are not required. g

--The presence in water, and aqueous a The proportions oi. the co per. salt and'trie chlorophenolate employed accordingto the nresent invention are such that a reciprocal activation occurs as between the copper ions and the This is evidenced by trichlorophenol molecules. 7 I the'fact that the control obtained with the combination of material issynergistic or greater than additive with respect to the controls obtainable with the individual components ofthe combinathin. The increase in eflectiveness' ismany-fold quantity as to introduce into the system the de-" --siredjconcentration of the toxic mixture.- .Other and the more surprising by. reason of the fact that copper-trlchlorophenolates in similar use have {a lowdegree of eflectiveness by comparison: hlsothe latter compounds are relatively" water-insolubleawhereby their introduction. into I aqueous systems is but diflicultly-accomplished. The present invention avoids such complications by reason 'of' the fact that the copper salt and phenolate may be introduced in asingle operation as a dry mixture or separately in a two step procedure and in either methodof operation are readily solubleinwaten. i

, any suitablegproportions of copper salt and phenolate may be employed provided only. that the selected amounts be such that in water solution a reciprocal activation is accomplished. In. practice it hasbeen' found that for an amount of soluble icopper salt embodying 1 part by weight of copper, an amount of phenolate prepared from or embodying from 0.1 to 30 parts byweightof trichlorophenol shou ld be employed. The effective concentra- -j 'tion-"of thecombination to be employed in. an 7 aqueous medium varies between 5 and 50 parts per million or higher depending upon the particvular organisms to be controlled and the temperature and other conditions under which control is to be accomplished.

Any water-soluble copper-salt may be employed 1 in accordance with the invention, e. g. coppersulfate, copper acetate, copper chloride,'copper bromide, copper nitrate, etc. The foregoing-compounds are all cupricderivatives. However, so-

lutions of cuprous ions are soon oxidized to the cupric form so that wall intents and purposes all-soluble copper salts are equivalents. Among the phenolates which are employed inicombinatron with the copper salt are sodium 2.4-5-t A further embodiment of the invention which The preierred'jembodiment of the invention concerns a combination of a copper ion-yelding' materiai such as a salt and a water-soluble salt of an unsymmetrical trichlor'ophenol. Such combination of unsymmetrical trichlorophenolate and water-soluble copper salt has been found to exert toxic eflectsagainst slime-forming organ! :isms to a degree-many times that characterizing similar combinations embodying the 2.4.6-trichlocombination of toxicants is generally used-in the amount of from'5 tdzoparts per million in water or other aqueous media.

operating in accordance with the. present invention, the combination of toxicahts maybe employed in any suitable manner. Thus, a dry phenolate such as soduim 2.4.5-trichlorophenolate may be ground with a solid "copper salt such as copper sulfate to obtain a finely-divided-toxicant'mixture which may be added directly; to a circulating systemat any point and distributed therefrom in solution throughout the body of liquid requiring treatment. Similarly, such mixture oftoxicants may be made, up in the form of briquettes and the circulating fluidpassingin contact therewith at such arate and in such a modes of operation include adding the phenolate and copper salt separately to the system" as crystalline solids, as dusts, as aqueous solutions; or, in the case of the phenolate, as a solution in water-miscible organic solvent. Regardlessofthe procedure employed, care should be exercised that there be no'reac'tion between the-copper salt I and phenolate prior to addition, since ithas been found that the pre-torme'd' copper salts of trichlorophen'ols are much less eflective against slime organisms than is'the combinationof copper ions and phenol molecules obtained when the copper salt and soluble phenolateper se are dissolved in the media to be preserved.

provides for an optimum control of the formation of certain types of slime deposits and operates to soften and dislodge previously deposited slime bodies from the surfaces of pipes, conduits,

and machinery is that of'employing with the mixture of toxicants a considerable excess of alkali. This procedure is particularly advantageous where. it is desired to flush a system containing heavy slime deposits, to accomplish a quick control of existing contamination, and to prevent a recurrence ofthe undesirable conditions under treatment. In such operation the alkali, in the form ofso'dium hydroxide or otherwise. may be added in conjunction with the phenolate and/or copper salt or separately as is convenient or practical.

The expression slime forming organism" as herein employed is inclusive of algae and of microeorganisms such as bacteria," yeast-like fungi, and molds. The micro-organisms maybe classified in a general way as (1) colifo'rm and coliform-like bacteria belonging to the genera Escherichia and Aerobacter; (zinon-spore-bear- V In this embodiment of the inven- 'tion, from 1'to 18 parts by weight of the phenolate is employed per part of copper salt. The

yeast-like fungi,

which th present special groups such as the ironfbacteria that sometimes develop in water supplies: pseudo yeasts and yeast-likeiungi such as Torula, Oidium, Monilia, Endomyces and related groups; and

(6) filamentous fungi oi the mold type including members oi the genera Penicllium, Aspergillus, Trichoderrna, Cladosporium, Botrytis, Acrostalagmus, Altern'aria, Bpicaria and Clonostachys. Representative slime formations and deposits as formed by these organisms are for! days in the caseoi iungi, and

V the control 01 a ephalosporium.

described as gelatinous or viscous from the nonspore-bearing bacteria, pasty or doughy from the stringy or ropy from" the spore-'- bearing bacteria, rubbery or leathery from the yeast-like fungi, and hard and matted from the yeast-like fungi and 'molds. Among the 'micro-' organisms included within the expression "slimeforming organisms are related bacteria, and particularly' those imparting odor to systems in in minutes exposure.

' of water.

I dissolving the copper salt and at 37' C. for 48 hours in the case oi bacteria. I Thesub-cultllres are then subjected to visual and/or microscopic examination to determine the, presence or ab-" sence of living organisms. ,No' e'ilort is'made toestimate degree oi control. all results being-rib ported as either plusor minus with respectito complete control for the particular'dilutiom-of toxicants employed. v

v 'Ex'smyu 1 a Sodium I 2.4.5-trichlorophenolate and sulfate;5H-z0 were employed in combination for variety of slime organisms. The proportions of the two materials were varied considerably and. in each instance the toxicity of the combination was determined by separately phenolate in'a" measured amount of water and thereaiteradding additional water to obtain dilutions of. as great as 1 part of the toxic combination in 80,000 Toxicity determinations were also carried out with aqueous solutions 01' sodium 2.4.55 trichlorophenolate alone and of copper sulfate alone. The following table sets forth the results obtained against representative slime-forming organisms in terms of the maximum dilutions of toxicant giving a complete killtoi the organism en sulfide gas or other products commonly found to cause corrosion in circulating water systems. In investigating the combination of toxicants to invention is directed and in comparin the constituents of such combinanations, the rapid killing action of the toxicant under test wastaken as the index of effectiveness. According to this toxicity determination, the ability of aqueous dilutions of toxicant to kill various micro-organisms in 10 minutes contact time and at -27 C. in fluid systems was observed. The exact ducing into a dilute solution of the toxicant in. water, a 0.5 cubic centimeter portion of a filtered culture of the organism in sterile potato-glucose broth dispersion. The resulting mixture is allowed to stand for 10 minutes at 25-27 C. with mild agitation. At the end of this time the mixture is sub-cultured in sterile potato-glucose broth and such sub-cultures incubated at 28 certain organisms at a dilution of procedure followed consists 01 intro- Tablet 5 A J i I, i I g Aerobader Aerobcder' Aerobacter Euherictla Penicillium Trichoderme Oidium-sp. mm,

'Ioxicantaerogma ceroqena (10am coll (slimy) (slime (slime- (elime-i'orm- (gummy) (slimy) (s im L I fi ing) 33mm) my I o v ipartbywtoopf i/ -f Greaterthan Greaterthan Greater-than Greeterthan Greaterthan Greater-than Greatertban Greater-than: fi 1454* '1-eo,ooo.- '1- 80,000. l-UMXX). 1 140,000. 1-804110. 180,000. l-KLM. 1 lohlfllgphghtollh. I V I y o pp suliate.&H:0.

B 1.75 by wt (in (In the (In In (In the no, um -2.4.5-trichlorophenolate. as rise 0. 252 art: by .--.-a.. dn dn fin (In do" d Do.

cm umhZLIB-gb f0 1108 D Sodh m Ab-trb Not en'ec- Not eflec- Not at! Not deter Between 1- Between l- Not efleo- Between 1- chlorophenolate. tive at 1- tive at ltive at lmined. 1,000 and 1,000 and tive at l- 600- aud i- Bill. 600. 4,600. l-2,500. 5m. 1, E. O o p p e r an i Not eii'eo- Not. oiled Not deter ....-do-. Not eiiec- Not ei'lec- Not eileo- Not etieotive lateJl ItO. rive at ltive at ,1- mined. tive at ltive at ltive at 1- at 1-20.

. 20. 2o. I which they are round and those producing hydroas It is evident from the foregoing table that each against all organisms at dilutions of 140,000. In

contrast, the constituents of the combination were relatively ineflective. The sodium 2.4.5-trichlorophenolate gave a rather selective control against from 14,000 to 12.5 0 and in other instances failed to control at. as low a dilution as 1-500. Similarly, copper sulfate failed. to show enectiveness against any of the test organisms at a dilution 01' 1-20. The control accomplished by the comblnationoi toxicants is seenvto be greater than additive and indicates a reciprocal activation between the copper salt and phenolate.

EXAhIPL! 2 Aerobacter aerogenes (gummy) was employed as a test organism against which combinations of C. 78 sodium 2.4.6-trichlorophenolate with copper sulterm employedcontrol determlnli- Y o! introilucina into til-"tor from to'flwtl tions were carried out with the phenolate alone. 'per milllon of a combination 0! (A) 1.0 port by The ioilowins table sets forth thereeults obweight oi water-soluble-copper salt and (B) irom V v tained in-termeoithe maximum dilutions aocomvl-to': 18 arts by weight or a water-soluble trl-. a complete. kill oi the organism in chlorophenolate. the cop salt and phenolate Y I @beinseddedsepemt v tqthesystem- 3m i .1o,ouo rial-204100? l j Between 1-10.000 mill-NM. a Greater thon l wflill Y Greater than r-a'mouoQ Y Between 1-1pm and Hon; Notoilectiveatl-N. I

names a, Y illimethod tor the control of slime formation]: in circulating water systems comprising thexetep h 0 a. similar iashion determinations were carorintroducins into the water from 5 to parts rled out in which the copper salt or 2.4.5-trlper million of b ti pf (4 1,0 part by ch oroph n l a c p dh a mixture o weight, or copper sulfate and. (B) from 1 to 18 gram molecular. weight of sodium 2.1.5-trichloroart by w ight of sodium 2.4. 5-trich1orophenophenolate and 0.5 gram molecular weight of cap 'l te er' sulfate These materials were applied at low 3. A method for the control of glime formation dilution for the control or representative slime in circulating water systems comprieing'theetep tormins fun bact ria. a d asts- It wa v of introducing into the water tree alkali and at found. that the concentration or copper 2.4.5'-trino least 5 par-taper million of a combination of (Al cmorophenolate required to accomplish control 1 1,0 part by weight or a. wate olublecopper-nalt, o! the slime organisms as a group was at leastl0 and .(B) from 1 to 18 parts by weightioi a water;

times that required for the combination'ot ohesoluble trichlorophenolate.

nolateand copper salt. This comparison was 4. A'method tor th'econtrol of slime formation" made on the basis of the maximum dilution of in circulating watet .mtem s comprising the step the copper phenolate and combination of toxlor introducing into the water at least 5 parts per cants to kill the test organisms ina 10 minute million ora. combination or (A) 1 .0 part by weight l .t or a waterluble copper salt and (B) ircml to exposureperiogl I 1. A method'for control oi eume formation 40 phenolate. in circulating water comprising the step 18: 5am by weight or c w t-ee w'; I 

